Search results for: evolution of deformation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2707

Search results for: evolution of deformation

1867 Nickel-Titanium Endodontic Instruments: The Evolution

Authors: Fadwa Chtioui

Abstract:

The field of endodontics has witnessed constant advancements in treatment methods and instrument design, particularly for nickel-titanium (NiTi) files. Despite these developments, it remains crucial for clinicians to have a thorough understanding of their characteristics and behavior to choose the appropriate instruments for different clinical and anatomical situations. Research Aim: The aim of this work is to study and discuss the impact of heat treatment developments on the properties of endodontic NiTi files, with the ultimate goal of providing ways to adapt these files to the anatomical features of dental roots. Methodology: This study involves both clinical cases and extensive bibliographic research. Findings: The study highlights the importance of heat treatment in the design and manufacture of NiTi files, as it significantly affects their physical and mechanical properties. It also provides insights into the ways in which NiTi files can be adapted to the complex geometries of dental roots for more effective endodontic treatments. Theoretical Importance: Theoretical implications of this study include a better understanding of the relationship between heat treatment and the properties of NiTi files, leading to improvements in both their manufacturing methods and clinical applications. Data Collection and Analysis Procedures: The data for this study was collected through clinical cases and an extensive review of relevant literature. Analysis was performed through qualitative and quantitative methods, examining the impact of heat treatment on the physical and mechanical properties of NiTi files. Questions Addressed: This study aims to answer questions concerning the properties of NiTi files and the impact of heat treatment on their behavior. It also seeks to examine ways in which these files can be adapted to complex dental root geometries for more effective endodontic treatments. Conclusion: In conclusion, this study emphasizes the importance of heat treatment in the design and manufacture of NiTi files, as it significantly impacts their physical and mechanical properties. Further research is necessary to explore additional methods for adapting NiTi files to the unique anatomies of dental roots to improve endodontic treatments further. Ultimately, this study provides valuable insights into the continued evolution of endodontic treatment and instrument design.

Keywords: endodontic files, nickel-titanium, tooth anatomy, heat treatment

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1866 Process of the Emergence and Evolution of Socio-Cultural Ideas about the "Asian States" In the Context of the Development of US Cinema in 1941-1945

Authors: Selifontova Darya Yurievna

Abstract:

The study of the process of the emergence and evolution of socio-cultural ideas about the "Asian states" in the context of the development of US cinema in 1941-1945 will contribute both to the approbation of a new approach to the classical subject and will allow using the methodological tools of history, political science, philology, sociology for understanding modern military-political, historical, ideological, socio-cultural processes on a concrete example. This is especially important for understanding the process of constructing the image of the Japanese Empire in the USA. Assessments and images of China and Japan in World War II, created in American cinema, had an immediate impact on the media, public sentiment, and opinions. During the war, the US cinema created new myths and actively exploited old ones, combining them with traditional Hollywood cliches - all this served as a basis for creating the image of China and the Japanese Empire on the screen, which were necessary to solve many foreign policy and domestic political tasks related to the construction of two completely different, but at the same time, similar images of Asia (China and the Japanese Empire). In modern studies devoted to the history of wars, the study of the specifics of the information confrontation of the parties is in demand. A special role in this confrontation is played by propaganda through cinema, which uses images, historical symbols, and stable metaphors, the appeal to which can form a certain public reaction. Soviet documentaries of the war years are proof of this. The relevance of the topic is due to the fact that cinema as a means of propaganda was very popular and in demand during the Second World War. This period was the time of creation of real masterpieces in the field of propaganda films, in the documentary space of the cinema of 1941 – 1945. The traditions of depicting the Second World War were laid down. The study of the peculiarities of visualization and mythologization of the Second World War in Soviet cinema is the most important stage for studying the development of the specifics of propaganda methods since the methods and techniques of depicting the war formed in 1941-1945 are also significant at the present stage of the study of society.

Keywords: asian countries, politics, sociology, domestic politics, USA, cinema

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1865 ISME: Integrated Style Motion Editor for 3D Humanoid Character

Authors: Ismahafezi Ismail, Mohd Shahrizal Sunar

Abstract:

The motion of a realistic 3D humanoid character is very important especially for the industries developing computer animations and games. However, this type of motion is seen with a very complex dimensional data as well as body position, orientation, and joint rotation. Integrated Style Motion Editor (ISME), on the other hand, is a method used to alter the 3D humanoid motion capture data utilised in computer animation and games development. Therefore, this study was carried out with the purpose of demonstrating a method that is able to manipulate and deform different motion styles by integrating Key Pose Deformation Technique and Trajectory Control Technique. This motion editing method allows the user to generate new motions from the original motion capture data using a simple interface control. Unlike the previous method, our method produces a realistic humanoid motion style in real time.

Keywords: computer animation, humanoid motion, motion capture, motion editing

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1864 Damage Micromechanisms of Coconut Fibers and Chopped Strand Mats of Coconut Fibers

Authors: Rios A. S., Hild F., Deus E. P., Aimedieu P., Benallal A.

Abstract:

The damage micromechanisms of chopped strand mats manufactured by compression of Brazilian coconut fiber and coconut fibers in different external conditions (chemical treatment) were used in this study. Mechanical analysis testing uniaxial traction were used with Digital Image Correlation (DIC). The images captured during the tensile test in the coconut fibers and coconut fiber mats showed an uncertainty of measurement in order centipixels. The initial modulus (modulus of elasticity) and tensile strength decreased with increasing diameter for the four conditions of coconut fibers. The DIC showed heterogeneous deformation fields for coconut fibers and mats and the displacement fields showed the rupture process of coconut fiber. The determination of poisson’s ratio of the mat was performed through of transverse and longitudinal deformations found in the elastic region.

Keywords: coconut fiber, mechanical behavior, digital image correlation, micromechanism

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1863 Experience of Using Expanding Polyurethane Resin for Ground Improvement Under Existing Shallow Foundations on The Arabian Peninsula

Authors: Evgeny N. Zakharin, Bartosz Majewski

Abstract:

Foaming polyurethane is a ground improvement technology that is increasingly used for foundation stabilization with differential settlement and controlled foundation structure lifting. This technology differs from conventional mineral grout due to its injection composition, which provides high-pressure expansion quickly due to a chemical reaction. The technology has proven efficient in the typical geological conditions of the United Arab Emirates. An in-situ trial foundation load test has been proposed to objectively assess the deformative and load-bearing characteristics of the soil after injection. The article provides a detailed description of the experiment carried out in field conditions. Based on the practical experiment's results and its finite element modeling, the deformation modulus of the soil after treatment was determined, which was more than five times higher than the initial value.

Keywords: chemical grout, expanding polyurethane resin, foundation remediation, ground improvement

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1862 Application of GIS Techniques for Analysing Urban Built-Up Growth of Class-I Indian Cities: A Case Study of Surat

Authors: Purba Biswas, Priyanka Dey

Abstract:

Worldwide rapid urbanisation has accelerated city expansion in both developed and developing nations. This unprecedented urbanisation trend due to the increasing population and economic growth has caused challenges for the decision-makers in city planning and urban management. Metropolitan cities, class-I towns, and major urban centres undergo a continuous process of evolution due to interaction between socio-cultural and economic attributes. This constant evolution leads to urban expansion in all directions. Understanding the patterns and dynamics of urban built-up growth is crucial for policymakers, urban planners, and researchers, as it aids in resource management, decision-making, and the development of sustainable strategies to address the complexities associated with rapid urbanisation. Identifying spatio-temporal patterns of urban growth has emerged as a crucial challenge in monitoring and assessing present and future trends in urban development. Analysing urban growth patterns and tracking changes in land use is an important aspect of urban studies. This study analyses spatio-temporal urban transformations and land-use and land cover changes using remote sensing and GIS techniques. Built-up growth analysis has been done for the city of Surat as a case example, using the GIS tools of NDBI and GIS models of the Built-up Urban Density Index and Shannon Entropy Index to identify trends and the geographical direction of transformation from 2005 to 2020. Surat is one of the fastest-growing urban centres in both the state and the nation, ranking as the 4th fastest-growing city globally. This study analyses the dynamics of urban built-up area transformations both zone-wise and geographical direction-wise, in which their trend, rate, and magnitude were calculated for the period of 15 years. This study also highlights the need for analysing and monitoring the urban growth pattern of class-I cities in India using spatio-temporal and quantitative techniques like GIS for improved urban management.

Keywords: urban expansion, built-up, geographic information system, remote sensing, Shannon’s entropy

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1861 Progressive Structural Capacity Loss Assessment

Authors: M. Zain, Thaung H. Aung, Naveed Anwar

Abstract:

During the service life, a structure may experience extreme loading conditions. The current study proposes a new methodology that covers the effect of uncertainty involved in gravity loadings on key structural elements of new and complex structures by emphasizing on a very realistic assumption that allows the 'Performance-Based Assessment' to be executed on the structure against the gravity loadings. The methodology does not require the complete removal of an element, instead, it permits the incremental reduction in the capacity of key structural elements and preserves the same stiffness of the member in each case of capacity loss. To demonstrate the application of the proposed methodology, a 13 story complex structure is selected that comprises of a diverse structural configuration. The results ensure the structural integrity against the applied gravity loadings, as well as the effectiveness of the proposed methodology.

Keywords: force-deformation relationship, gravity loading, incremental capacity reduction, multi-linear plastic link element, SAP2000, stiffness

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1860 External Sulphate Attack: Advanced Testing and Performance Specifications

Authors: G. Massaad, E. Roziere, A. Loukili, L. Izoret

Abstract:

Based on the monitoring of mass, hydrostatic weighing, and the amount of leached OH- we deduced the nature of leached and precipitated minerals, the amount of lost aggregates and the evolution of porosity and cracking during the sulphate attack. Using these information, we are able to draw the volume / mass changes brought by mineralogical variations and cracking of the cement matrix. Then we defined a new performance indicator, the averaged density, capable to resume along the test of sulphate attack the occurred physicochemical variation occurred in the cementitious matrix and then highlight.

Keywords: monitoring strategy, performance indicator, sulphate attack, mechanism of degradation

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1859 Experimental Investigation and Constitutive Modeling of Volume Strain under Uniaxial Strain Rate Jump Test in HDPE

Authors: Rida B. Arieby, Hameed N. Hameed

Abstract:

In this work, tensile tests on high density polyethylene have been carried out under various constant strain rate and strain rate jump tests. The dependency of the true stress and specially the variation of volume strain have been investigated, the volume strain due to the phenomena of damage was determined in real time during the tests by an optical extensometer called Videotraction. A modified constitutive equations, including strain rate and damage effects, are proposed, such a model is based on a non-equilibrium thermodynamic approach called (DNLR). The ability of the model to predict the complex nonlinear response of this polymer is examined by comparing the model simulation with the available experimental data, which demonstrate that this model can represent the deformation behavior of the polymer reasonably well.

Keywords: strain rate jump tests, volume strain, high density polyethylene, large strain, thermodynamics approach

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1858 Pattern of Stress Distribution in Different Ligature-Wire-Brackets Systems: A FE and Experimental Analysis

Authors: Afef Dridi, Salah Mezlini

Abstract:

Since experimental devices cannot calculate stress and deformation of complex structures. The Finite Element Method FEM has been widely used in several fields of research. One of these fields is orthodontics. The advantage of using such a method is the use of an accurate and non invasive method that allows us to have a sufficient data about the physiological reactions can happening in soft tissues. Most of researches done in this field were interested in the study of stresses and deformations induced by orthodontic apparatus in soft tissues (alveolar tissues). Only few studies were interested in the distribution of stress and strain in the orthodontic brackets. These studies, although they tried to be as close as possible to real conditions, their models did not reproduce the clinical cases. For this reason, the model generated by our research is the closest one to reality. In this study, a numerical model was developed to explore the stress and strain distribution under the application of real conditions. A comparison between different material properties was also done.

Keywords: visco-hyperelasticity, FEM, orthodontic treatment, inverse method

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1857 Literature Review and Evaluation of the Internal Marketing Theory

Authors: Hsiao Hsun Yuan

Abstract:

Internal marketing was proposed in 1970s. The theory of the concept has continually changed over the past forty years. This study discussed the following themes: the definition and implication of internal marketing, the progress of its development, and the evolution of its theoretical model. Moreover, the study systematically organized the strategies of the internal marketing theory adopted on enterprise and how they were put into practice. It also compared the empirical studies focusing on how the existent theories influenced the important variables of internal marketing. The results of this study are expected to serve as references for future exploration of the boundary and studies aiming at how internal marketing is applied to different types of enterprises.

Keywords: corporate responsibility, employee organizational performance, internal marketing, internal customer

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1856 A Parallel Poromechanics Finite Element Method (FEM) Model for Reservoir Analyses

Authors: Henrique C. C. Andrade, Ana Beatriz C. G. Silva, Fernando Luiz B. Ribeiro, Samir Maghous, Jose Claudio F. Telles, Eduardo M. R. Fairbairn

Abstract:

The present paper aims at developing a parallel computational model for numerical simulation of poromechanics analyses of heterogeneous reservoirs. In the context of macroscopic poroelastoplasticity, the hydromechanical coupling between the skeleton deformation and the fluid pressure is addressed by means of two constitutive equations. The first state equation relates the stress to skeleton strain and pore pressure, while the second state equation relates the Lagrangian porosity change to skeleton volume strain and pore pressure. A specific algorithm for local plastic integration using a tangent operator is devised. A modified Cam-clay type yield surface with associated plastic flow rule is adopted to account for both contractive and dilative behavior.

Keywords: finite element method, poromechanics, poroplasticity, reservoir analysis

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1855 The Soliton Solution of the Quadratic-Cubic Nonlinear Schrodinger Equation

Authors: Sarun Phibanchon, Yuttakarn Rattanachai

Abstract:

The quadratic-cubic nonlinear Schrodinger equation can be explained the weakly ion-acoustic waves in magnetized plasma with a slightly non-Maxwellian electron distribution by using the Madelung's fluid picture. However, the soliton solution to the quadratic-cubic nonlinear Schrodinger equation is determined by using the direct integration. By the characteristics of a soliton, the solution can be claimed that it's a soliton by considering its time evolution and their collisions between two solutions. These results are shown by applying the spectral method.

Keywords: soliton, ion-acoustic waves, plasma, spectral method

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1854 Soil Moisture Regulation in Irrigated Agriculture

Authors: I. Kruashvili, I. Inashvili, K. Bziava, M. Lomishvili

Abstract:

Seepage capillary anomalies in the active layer of soil, related to the soil water movement, often cause variation of soil hydrophysical properties and become one of the main objectives of the hydroecology. It is necessary to mention that all existing equations for computing the seepage flow particularly from soil channels, through dams, bulkheads, and foundations of hydraulic engineering structures are preferable based on the linear seepage law. Regarding the existing beliefs, anomalous seepage is based on postulates according to which the fluid in free volume is characterized by resistance against shear deformation and is presented in the form of initial gradient. According to the above-mentioned information, we have determined: Equation to calculate seepage coefficient when the velocity of transition flow is equal to seepage flow velocity; by means of power function, equations for the calculation of average and maximum velocities of seepage flow have been derived; taking into consideration the fluid continuity condition, average velocity for calculation of average velocity in capillary tube has been received.

Keywords: seepage, soil, velocity, water

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1853 Redefining Lesbian Representation: The Evolution of Queer Female Desire in the Films of Céline Sciamma

Authors: Athira Sanjeev

Abstract:

The portrayal of lesbianism in cinema has undergone significant transformations. This study explores the evolving portrayal of lesbianism in the films of French director Céline Sciamma, focusing on how her works have redefined the representation of queer women in contemporary cinema. Through an analysis of Water Lilies (2007), Tomboy (2011), and Portrait of a Lady on Fire (2019), the study investigates the ways in which Sciamma’s films diverge from traditional depictions of lesbianism in film, which often relied on either fetishization or tragedy. Instead, Sciamma adopts a quiet, minimalist style that foregrounds emotional intimacy, offering a more nuanced and authentic portrayal of lesbian relationships. Through a comparative analysis of these films, this research explores the thematic and stylistic progression of Sciamma’s portrayal of lesbianism, highlighting her commitment to centering queer female experiences. The research highlights Sciamma's commitment to focusing on the complexities of desire, identity formation, and the female gaze, particularly through her use of visual storytelling, character development, and narrative silence. Her films emphasize the fluidity of gender and sexuality, portraying lesbianism not as a fixed identity but as part of a broader spectrum of human desire. Sciamma’s nuanced approach resists the traditional marginalization of lesbian characters, allowing them to exist as individuals rather than as plot devices or objects of spectacle. This study draws from queer theory and feminist film criticism to examine how Sciamma challenges conventional heteronormative narratives, prioritizes the female gaze, and subverts traditional cinematic representations of lesbian desire. It also explores how her work contributes to a broader conversation on the representation of queerness in contemporary French cinema, challenging heteronormative paradigms and offering new possibilities for depicting female relationships on screen. By tracing the evolution of her films, this research contributes to broader discussions on LGBTQ+ visibility in cinema and the cultural significance of lesbian representation in contemporary cinema.

Keywords: female gaze, feminist film criticism, lesbianism in cinema, queer theory

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1852 The Evolution and Driving Forces Analysis of Urban Spatial Pattern in Tibet Based on Archetype Theory

Authors: Qiuyu Chen, Bin Long, Junxi Yang

Abstract:

Located in the southwest of the "roof of the world", Tibet is the origin center of Tibetan Culture.Lhasa, Shigatse and Gyantse are three famous historical and cultural cities in Tibet. They have always been prominent political, economic and cultural cities, and have accumulated the unique aesthetic orientation and value consciousness of Tibet's urban construction. "Archetype" usually refers to the theoretical origin of things, which is the collective unconscious precipitation. The archetype theory fundamentally explores the dialectical relationship between image expression, original form and behavior mode. By abstracting and describing typical phenomena or imagery of the archetype object can observe the essence of objects, explore ways in which object phenomena arise. Applying archetype theory to the field of urban planning helps to gain insight, evaluation, and restructuring of the complex and ever-changing internal structural units of cities. According to existing field investigations, it has been found that Dzong, Temple, Linka and traditional residential systems are important structural units that constitute the urban space of Lhasa, Shigatse and Gyantse. This article applies the thinking method of archetype theory, starting from the imagery expression of urban spatial pattern, using technologies such as ArcGIS, Depthmap, and Computer Vision to descriptively identify the spatial representation and plane relationship of three cities through remote sensing images and historical maps. Based on historical records, the spatial characteristics of cities in different historical periods are interpreted in a hierarchical manner, attempting to clarify the origin of the formation and evolution of urban pattern imagery from the perspectives of geopolitical environment, social structure, religious theory, etc, and expose the growth laws and key driving forces of cities. The research results can provide technical and material support for important behaviors such as urban restoration, spatial intervention, and promoting transformation in the region.

Keywords: archetype theory, urban spatial imagery, original form and pattern, behavioral driving force, Tibet

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1851 The Evolution of the Piano Preludes by Focusing on Bach, Chopin and Debussy’s Work

Authors: Parham Bakhtiari

Abstract:

This document follows the development of the prelude genre by analyzing specific pieces from a representative selection of composer from Bach to Shostakovich in every era. The research aims to prove the existence of an evolutionary axis in the genre of prelude's history, which is believed to be fading. In this research, Bach, Chopin, and Debussy's works are demonstrated and explored by creating a definition of the genre on his own terms and having an impact on future composers in the following generations. Taking into account, the educational aspect of the prelude and its connection to the genre of study, a brief conversation about it is also provided with an assessment of shorter versions of the genre, for instance, Chopin's preludes.

Keywords: music, piano, prelude, Bach, Chopin, Debussy

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1850 Quantum Entanglement and Thermalization in Superconducting Two-Qubit Systems

Authors: E. Karami, M. Bohloul, P. Najmadi

Abstract:

The superconducting system is a suitable system for quantum computers. Quantum entanglement is a fundamental phenomenon that is key to the power of quantum computers. Quantum entanglement has been studied in different superconducting systems. In this paper, we are investigating a superconducting two-qubit system as a macroscopic system. These systems include two coupled Quantronium circuits. We calculate quantum entanglement and thermalization for system evolution and compare them. We observe, thermalization and entanglement have different behavior, and equilibrium thermal state has maximum entanglement.

Keywords: macroscopic system, quantum entanglement, thermalization, superconducting system

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1849 The Chromatic Identity of the Ancestral Architecture of the Ksour of Bechar, Algeria

Authors: Racha Ghariri, Khaldia Belkheir, Assil Ghariri

Abstract:

In this paper, the researchers present a part of their research on the colors of the city of Bechar (Algeria). It is about a chromatic study of the ancient architecture of the Ksour. Being a subject of intervention, regarding their degradable state, the Ksour are the case of their study, especially that the subject of color does not occupy, virtually, the involved on these heritage sites. This research aims to put the basics for methods which allow to know what to preserve as a color and how to do so, especially during a restoration, and to understand the evolution of the chromatic state of the city.

Keywords: architecture/colours, chromatic identity, geography of colour, regional palette, chromatic architectural analysis

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1848 The Evolution of Architecture through Digital: A Survey on Fashion Catwalk Becoming Digital

Authors: Valeria Minucciani, Maria Maddalena Margaria

Abstract:

While mathematical tools that make digital architecture possible are very sophisticated and advanced, theoretical development of digital architecture (intended as a discipline that integrates or replaces the real architecture) is not. The fashion show, that involves interiors architecture, exhibit design and scenography, has been exploiting for ten years the opportunities offered by digital technologies. To gain greater visibility and to reach a wider audience, high-level experimentations have been performed. The aim of this paper is in investigating, through the analysis of some cases of virtual fashion shows, the 'architectural' impact of the virtual conception of interior space.

Keywords: digital interiors, exhibit, fashion catwalk, architectural theory

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1847 Research on the Spatial Organization and Collaborative Innovation of Innovation Corridors from the Perspective of Ecological Niche: A Case Study of Seven Municipal Districts in Jiangsu Province, China

Authors: Weikang Peng

Abstract:

The innovation corridor is an important spatial carrier to promote regional collaborative innovation, and its development process is the spatial re-organization process of regional innovation resources. This paper takes the Nanjing-Zhenjiang G312 Industrial Innovation Corridor, which involves seven municipal districts in Jiangsu Province, as empirical evidence. Based on multi-source spatial big data in 2010, 2016, and 2022, this paper applies triangulated irregular network (TIN), head/tail breaks, regional innovation ecosystem (RIE) niche fitness evaluation model, and social network analysis to carry out empirical research on the spatial organization and functional structural evolution characteristics of innovation corridors and their correlation with the structural evolution of collaborative innovation network. The results show, first, the development of innovation patches in the corridor has fractal characteristics in time and space and tends to be multi-center and cluster layout along the Nanjing Bypass Highway and National Highway G312. Second, there are large differences in the spatial distribution pattern of niche fitness in the corridor in various dimensions, and the niche fitness of innovation patches along the highway has increased significantly. Third, the scale of the collaborative innovation network in the corridor is expanding fast. The core of the network is shifting from the main urban area to the periphery of the city along the highway, with small-world and hierarchical levels, and the core-edge network structure is highlighted. With the development of the Innovation Corridor, the main collaborative mode in the corridor is changing from collaboration within innovation patches to collaboration between innovation patches, and innovation patches with high ecological suitability tend to be the active areas of collaborative innovation. Overall, polycentric spatial layout, graded functional structure, diversified innovation clusters, and differentiated environmental support play an important role in effectively constructing collaborative innovation linkages and the stable expansion of the scale of collaborative innovation within the innovation corridor.

Keywords: innovation corridor development, spatial structure, niche fitness evaluation model, head/tail breaks, innovation network

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1846 Structural and Microstructural Analysis of White Etching Layer Formation by Electrical Arcing Induced on the Surface of Rail Track

Authors: Ali Ahmed Ali Al-Juboori, H. Zhu, D. Wexler, H. Li, C. Lu, J. McLeod, S. Pannila, J. Barnes

Abstract:

A number of studies have focused on the formation mechanics of white etching layer and its origin in the railway operation. Until recently, the following hypotheses consider the precise mechanics of WELs formation: (i) WELs are the result of thermal process caused by wheel slip; (ii) WELs are mechanically induced by severe plastic deformation; (iii) WELs are caused by a combination of thermo-mechanical process. The mechanisms discussed above lead to occurrence of white etching layers on the area of wheel and rail contact. This is because the contact patch which is the active point of the wheel on the rail is exposed to highest shear stresses which result in localised severe plastic deformation; and highest rate of heat caused by wheel slipe during excessive traction or braking effort. However, if the WELs are not on the running band area, it would suggest that there is another cause of WELs formation. In railway system, particularly electrified railway, arcing phenomenon has been occurring more often and regularly on the rails. In electrified railway, the current is delivered to the train traction motor via contact wires and then returned to the station via the contact between the wheel and the rail. If the contact between the wheel and the rail is temporarily losing, due to dynamic vibration, entrapped dirt or water, lubricant effect or oxidation occurrences, high current can jump through the gap and results in arcing. The other resources of arcing also include the wheel passage the insulated joint and lightning on a train during bad weather. During the arcing, an extensive heat is generated and speared over a large area of top surface of rail. Thus, arcing is considered another heat source in the rail head (rather than wheel slipe) that results in microstructural changes and white etching layer formation. A head hardened (HH) rail steel, cut from a curved rail truck was used for the investigation. Samples were sectioned from a depth of 10 mm below the rail surface, where the material is considered to be still within the hardened layer but away from any microstructural changes on the top surface layer caused by train passage. These samples were subjected to electrical discharges by using Gas Tungsten Arc Welding (GTAW) machine. The arc current was controlled and moved along the samples surface in the direction of travel, as indicated by an arrow. Five different conditions were applied on the surface of the samples. Samples containing pre-existed WELs, taken from ex-service rail surface, were also considered in this study for comparison. Both simulated and ex-serviced WELs were characterised by advanced methods including SEM, TEM, TKD, EDS, XRD. Samples for TEM and TKFD were prepared by Focused Ion Beam (FIB) milling. The results showed that both simulated WELs by electrical arcing and ex-service WEL comprise similar microstructure. Brown etching layer was found with WELs and likely induced by a concurrent tempering process. This study provided a clear understanding of new formation mechanics of WELs which contributes to track maintenance procedure.

Keywords: white etching layer, arcing, brown etching layer, material characterisation

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1845 Calcium Silicate Bricks – Ultrasonic Pulse Method: Effects of Natural Frequency of Transducers on Measurement Results

Authors: Jiri Brozovsky

Abstract:

Modulus of elasticity is one of the important parameters of construction materials, which considerably influence their deformation properties and which can also be determined by means of non-destructive test methods like ultrasonic pulse method. However, measurement results of ultrasonic pulse methods are influenced by various factors, one of which is the natural frequency of the transducers. The paper states knowledge about influence of natural frequency of the transducers (54; 82 and 150kHz) on ultrasonic pulse velocity and dynamic modulus of elasticity (Young's Dynamic modulus of elasticity). Differences between ultrasonic pulse velocity and dynamic modulus of elasticity were found with the same smallest dimension of test specimen in the direction of sounding and density their value decreases as the natural frequency of transducers grew.

Keywords: calcium silicate brick, ultrasonic pulse method, ultrasonic pulse velocity, dynamic modulus of elasticity

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1844 Active Control of Multiferroic Composite Shells Using 1-3 Piezoelectric Composites

Authors: S. C. Kattimani

Abstract:

This article deals with the analysis of active constrained layer damping (ACLD) of smart multiferroic or magneto-electro-elastic doubly curved shells. The kinematics of deformations of the multiferroic doubly curved shell is described by a layer-wise shear deformation theory. A three-dimensional finite element model of multiferroic shells has been developed taking into account the electro-elastic and magneto-elastic couplings. A simple velocity feedback control law is employed to incorporate the active damping. Influence of layer stacking sequence and boundary conditions on the response of the multiferroic doubly curved shell has been studied. In addition, for the different orientation of the fibers of the constraining layer, the performance of the ACLD treatment has been studied.

Keywords: active constrained layer damping (ACLD), doubly curved shells, magneto-electro-elastic, multiferroic composite, smart structures

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1843 Improvement on a CNC Gantry Machine Structure Design for Higher Machining Speed Capability

Authors: Ahmed A. D. Sarhan, S. R. Besharaty, Javad Akbaria, M. Hamdi

Abstract:

The capability of CNC gantry milling machines in manufacturing long components has caused the expanded use of such machines. On the other hand, the machines’ gantry rigidity can reduce under severe loads or vibration during operation. Indeed, the quality of machining is dependent on the machine’s dynamic behavior throughout the operating process. For this reason, this type of machines has always been used prudently and are non efficient. Therefore, they can usually be employed for rough machining and may not produce adequate surface finishing. In this paper, a CNC gantry milling machine with the potential to produce good surface finish has been designed and analyzed. The lowest natural frequency of this machine is 202 Hz at all motion amplitudes with a full range of suitable frequency responses. Meanwhile, the maximum deformation under dead loads for the gantry machine is 0.565µm, indicating that this machine tool is capable of producing higher product quality.

Keywords: frequency response, finite element, gantry machine, gantry design, static and dynamic analysis

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1842 Three-Dimensional Numerical Simulation of Drops Suspended in Poiseuille Flow: Effect of Reynolds Number

Authors: A. Nourbakhsh

Abstract:

A finite difference/front tracking method is used to study the motion of three-dimensional deformable drops suspended in plane Poiseuille flow at non-zero Reynolds numbers. A parallel version of the code was used to study the behavior of suspension on a reasonable grid resolution (grids). The viscosity and density of drops are assumed to be equal to that of the suspending medium. The effect of the Reynolds number is studied in detail. It is found that drops with small deformation behave like rigid particles and migrate to an equilibrium position about half way between the wall and the center line (the Segre-Silberberg effect). However, for highly deformable drops there is a tendency for drops to migrate to the middle of the channel, and the maximum concentration occurs at the center line. The effective viscosity of suspension and the fluctuation energy of the flow across the channel increases with the Reynolds number of the flow.

Keywords: suspensions, Poiseuille flow, effective viscosity, Reynolds number

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1841 Evaluation of Flange Effects on the Lateral In-Plane Response of Brick Masonry Walls

Authors: Hizb Ullah Sajid, Muhammad Ashraf, Naveed Ahmad Qaisar Ali, Sikandar Hayat Sajid

Abstract:

This research study investigates experimentally the effects of flanges (transverse walls) on the lateral in-plane response of brick masonry walls. The experimental work included lateral in-plane quasi-static cyclic tests on full-scale walls (both with & without flanges). The flanges were introduced at both ends of the in-plane wall. In particular the damage mechanism, lateral in-plane stiffness & strength, deformability and energy dissipation of the two classes of walls are compared and the differences are quantified to help understand the effects of flanges on the in-plane response of masonry walls. The available analytical models for the in-plane shear strength & deformation evaluation of masonry walls are critically analyzed. Recommendations are made for the lateral in-plane capacity assessment of brick masonry walls including the contribution of transverse walls.

Keywords: brick masonry, damage mechanism, flanges effects, in-plane response

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1840 Crushing Behaviour of Thin Tubes with Various Corrugated Sections Using Finite Element Modelling

Authors: Shagil Akhtar, Syed Muneeb Iqbal, Mohammed R. Rahim

Abstract:

Common steel tubes with similar confines were used in simulation of tubes with distinctive type of corrugated sections. These corrugated cross-sections were arc-tangent, triangular, trapezoidal and square corrugated sections. The outcome of fluctuating structures of tube cross-section shape on the deformation feedback, collapse form and energy absorption characteristics of tubes under quasi-static axial compression have been prepared numerically. The finite element package of ANSYS Workbench was applied in the current analysis. The axial load-displacement products accompanied by the fold formation of disparate tubes were inspected and compared. Deviation of the initial peak load and the mean crushing force of the tubes with distinctive cross-sections were conscientiously examined.

Keywords: absorbed energy, axial loading, corrugated tubes, finite element, initial peak load, mean crushing force

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1839 Proecological Antioxidants for Stabilisation of Polymeric Composites

Authors: A. Masek, M. Zaborski

Abstract:

Electrochemical oxidation of dodecyl gallate (lauryl gallate), the main monomer flavanol found in green tea, was investigated on platinum electrodes using cyclic voltammetry (CV) and differential pulse (DPV) methods. The rate constant, electron transfer coefficient and diffusion coefficients were determined for dodecyl gallate electrochemical oxidation. The oxidation mechanism proceeds in sequential steps related to the hydroxyl groups in the aromatic ring of dodecyl gallate. Confirmed antioxidant activity of lauryl gallate verified its use in polymers as an environment-friendly stabiliser to improve the resistance to aging of the elastomeric materials. Based on the energy change of the deformation, cross-linking density and time of the oxygen induction with the TG method, we confirmed the high antioxidant activity of lauryl gallate in polymers. Moreover, the research on biodegradation confirmed the environment-friendly influence of the antioxidant by increasing the susceptibility of the elastomeric materials to disintegration by mildew mushrooms.

Keywords: polymers, flavonoids, stabilization, ageing

Procedia PDF Downloads 374
1838 Identification of Coauthors in Scientific Database

Authors: Thiago M. R Dias, Gray F. Moita

Abstract:

The analysis of scientific collaboration networks has contributed significantly to improving the understanding of how does the process of collaboration between researchers and also to understand how the evolution of scientific production of researchers or research groups occurs. However, the identification of collaborations in large scientific databases is not a trivial task given the high computational cost of the methods commonly used. This paper proposes a method for identifying collaboration in large data base of curriculum researchers. The proposed method has low computational cost with satisfactory results, proving to be an interesting alternative for the modeling and characterization of large scientific collaboration networks.

Keywords: extraction, data integration, information retrieval, scientific collaboration

Procedia PDF Downloads 388